Title : A rare case of COVID-19 complicated with severe pneumonia and acute arterial thrombosis of a lower limb
Abstract:
The COVID-19 pandemic demonstrated the risks for thrombotic complications associated with acute respiratory failure. Severe forms are associated with a hypercoagulable state due to excessive inflammation, hyperfibrinogenemia, hypoxia, altered angiotensin-converting enzyme 2, and endothelial injury creating conditions for thrombus formation. It has also been suggested that COVID-19 infection likely induces a process of immune system hyperactivation known as immunothrombosis, in which activated neutrophils and monocytes interact with platelets and the coagulation cascade, leading to thrombus formation. Studies suggest that the risk of arterial thrombosis increases with high severity of lung involvement. Systematic reviews and studies have shown that lower extremity arterial thrombosis in COVID-19 is associated with high mortality, amputation, and ineffective interventions.
We present a case of a 58-year-old man admitted to the Intensive Care Unit (ICU) of the Military Medical Academy - Sofia with the picture of severe respiratory failure based on massive bilateral pneumonia caused by SARS-CoV-2. The patient was febrile, with tachydyspnea and O2 saturation of 78% on ambient air, elevated values of C - reactive protein (CRP), lactate dehydrogenase (LDH), and fibrinogen, with normal d-dimer values. No concomitant diseases. Onset of symptoms - cough and fever, general weakness, dated from 1 week before hospitalization, when he also had a positive RT-PCR for SARS-CoV-2. The initial therapy included Levofloxacin, Piperacylline/Tazobactam, Fluconazole, corticosteroids, gastroprotector, and low molecular weight heparin at a dose of 2x 5,700 anti-Xa IU. Oxygen delivery was through a high oxygen concentration mask, with a tank balloon at a rate of up to 15L/min. On the fifth day of admission, the patient complained of severe pain in the right leg, which was colder and paler. D-dimer showed elevated values. Doppler examination revealed thrombosis of a. femoralis superficialis and thrombendarterectomy was performed. Therapy with Heparin in continuous infusion and Pentoxifylline was started. Two days later, there were no pulsations of plantar arteries and a purplish discoloration of the skin of the right foot. Emergency subtalar amputation was undertaken and Iloprost was added to the therapy. On the 20th day of admission, the patient was in improved general condition, with respiratory failure controlled, no need for oxygen therapy, and improved paraclinical parameters. He was discharged from the ICU and transferred to the Vascular Surgery Clinic for further treatment.
The case demonstrates that severe respiratory failure in COVID-19 predisposes to a prothrombotic state and endothelial injury, increasing the risk of arterial and venous thrombosis, and that prophylaxis with low molecular weight heparins does not completely eliminate the risk of thrombotic complications. Arterial thrombotic events increase the risk of death by 3-fold in patients with COVID-19 and demonstrate the critical need to develop effective preventive measures. Clinical judgment to initiate prophylactic anticoagulation should be made regardless of D-dimer level, as not all cases with arterial thrombosis have high D-dimers.
